[2] Emily Cecil married the marquess, then Lord Delvin, on 29 May 1812, at Hatfield House, Hertfordshire.
After the death of their infant son, Lord Delvin, they separated again, and it was agreed that their daughter would remain in the care of her mother; a legal battle ensued and custody was awarded to the earl.
[4] The marchioness later claimed that her mother-in-law, the former Countess of Westmeath, had recommended her to "make use of your prettiness" with the Duke of Wellington, in order to promote her husband's career.
[4] In 1825, the marchioness sought a legal separation from her husband in Ireland's ecclesiastical courts on the grounds of adultery and cruelty, after the marquess had been given a prison sentence for persistent duelling with those he believed to be his wife's lovers.
[3] He was persuaded to sign a financial settlement ensuring that his daughter would inherit a large proportion of his estate.